Accessibility navigation


Alternatives to Sedum on green roofs: Can broad leaf perennial plants offer better ‘cooling service’?

Blanusa, T., Vaz Monteiro, M. M., Fantozzi, F., Vysini, E., Li, Y. and Cameron, R. W.F. (2012) Alternatives to Sedum on green roofs: Can broad leaf perennial plants offer better ‘cooling service’? Building and Environment, 59. pp. 99-106. ISSN 0360-1323

[img]
Preview
Text - Accepted Version
· Please see our End User Agreement before downloading.

387kB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1016/j.buildenv.2012.08.011

Abstract/Summary

Green roof plants alter the microclimate of building roofs and may improve roof insulation. They act by providing cooling by shading, but also through transpiration of water through their stomata. However, leaf surfaces can become warmer when plants close the stomata and decrease water loss in response to drying substrate (typically associated with green roofs during summers), also reducing transpirational cooling. By using a range of contrasting plant types (Sedum mix – an industry green roof ‘standard’, Stachys byzantina, Bergenia cordifolia and Hedera hibernica) we tested the hypothesis that plants differ in their ‘cooling potential’. We firstly examined how leaf morphology influenced leaf temperature and how drying substrate altered that response. Secondly, we investigated the relationship between leaf surface temperatures and the air temperatures immediately above the canopies (i.e. potential to provide aerial cooling). Finally we measured how the plant type influenced the substrate temperature below the canopy (i.e. potential for building cooling). In our experiments Stachys outperformed the other species in terms of leaf surface cooling (even in drying substrate, e.g. 5 oC cooler compared with Sedum), substrate cooling beneath its canopy (up to 12 oC) and even - during short intervals over hottest still periods - the air above the canopy (up to 1 oC, when soil moisture was not limited). We suggest that the choice of plant species on green roofs should not be entirely dictated by what survives on the shallow substrates of extensive systems, but consideration should be given to supporting those species providing the greatest eco-system service potential.

Item Type:Article
Refereed:Yes
Divisions:Life Sciences > School of Agriculture, Policy and Development > Biodiversity, Crops and Agroecosystems Division- DO NOT USE
Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
Interdisciplinary centres and themes > Soil Research Centre
ID Code:29002
Publisher:Elsevier

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation